1. Field of the Invention.
The invention relates generally to integrated computer modules and, more specifically, to an integrated computer module of compact construction having an intermediate plate which captures a magnetic disk drive in the module and protects the disk drive from electromagnetic interference.
2. Description of the Related Art
Today""s personal computers (PC""s) are usually sold in a desktop configuration or a notebook configuration. Desktop PC""s are generally housed in a relatively large chassis containing a main printed circuit board or xe2x80x9cmotherboardxe2x80x9d and other components that are incorporated into or connected to the motherboard. The components may be located inside or outside of the chassis. Typical internal components include a power supply, a central processing unit (CPU), random access memory (RAM), a mass storage device such as a magnetic disk drive, expansion cards connected to a bus on the motherboard, and various peripherals mounted on xe2x80x9crailsxe2x80x9d in xe2x80x9cbaysxe2x80x9d within the chassis and electrically connected to the motherboard or an associated expansion card by a ribbon cable or the like. Typical expansion cards are a SCSI adapter, a sound adapter, and a network adapter. Typical bay-mounted peripherals are a magnetic disk drive, a floppy drive, a tape drive or a CD-ROM drive. Typical external xe2x80x9cperipheralsxe2x80x9d include user input devices such as a keyboard, a mouse, a microphone, a joystick, a graphics tablet or a scanner) and user output devices such as speakers a printer, and a video display device (e.g. a CRT display or an LCD display). The video adapter that controls the display, as with other adapters, may be integrated into the motherboard or provided on a separate expansion card.
The users of desktop PC""s may be divided into two divergent groups: (1) experienced users who understand the individual components and tend to frequently upgrade their PC""s by replacing such components, and (2) new users who do not understand or even want to understand the individual components. The latter group may prefer to replace the entire PC, if they upgrade at all. With respect to both groups, however, it has been observed that the need or desire to upgrade occurs far sooner with respect to some components than with respect to other components. In particular, users more frequently upgrade the CPU, the RAM, the magnetic disk drive, and the video adapter. These upgrades tend to provide more capacity and more speed because of rapid technological advancements on the part of manufacturers in response to ever-increasing demands from ever more complicated and more graphics intensive software applications and an associated increase in file sizes. Both user-types less frequently need or desire to upgrade the monitor, the speakers, the keyboard or the power supply, however, because these latter components have withstood the test of time and employ technologies that are less prone to obsolescence.
These inventors expect that the computer paradigm will move from a large chassis full of individual components of different manufacture toward a readily upgraded system consisting of two primary components: (1) an integrated computer module that compactly houses the frequently upgraded components (e.g. the CPU, the memory, the disk drive, and the video adapter) and provides a module connector for interfacing the module""s electronics with peripherals, and (2) a xe2x80x9chost assemblyxe2x80x9d with a docking bay that receives the module and provides a host connector that mates with the module connector. The host assembly can comprise any xe2x80x9cshellxe2x80x9d that includes the bay that receives the integrated computer module. The docking bay may be in a host assembly that doubles as a peripheral or in an intermediate assembly that is connected to conventional peripherals. The host assembly, for example, may function and appear generally like a conventional CRT display, save for the addition of the docking bay. A CRT-like host assembly of this nature would also provide a first connector for receiving input from a keyboard and, in all likelihood, a second connector for receiving input from a mouse. As another example, the host assembly may appear like a conventional tower chassis that contains a docking bay for receiving the module, and suitable electronics (e.g. a PCB, cables, and so on) to interface the integrated computer module to conventional expansion cards via an expansion bus, and to conventional peripherals like a display, a keyboard, and a mouse, via connector ports built-in to the host assembly or carried by an expansion card.
There are a number challenges associated with packing computer components and storage capability into a small integrated computer module. One such challenge is attaching the magnetic disk drive within the module in a secure, cost-effective manner. Another challenge is making sure the analog circuitry associated with the magnetic disk drive, which operates at low voltage levels and is very sensitive to EMI, functions properly in the vicinity of the microprocessor which operates at very high power and at very high clock speeds. Computer modules and associated bays have already been proposed. For example, in U.S. Pat. No. 5,463,742 that issued to Kobayashi in 1995, assigned to Hitachi, the inventor discloses a xe2x80x9cpersonal processor modulexe2x80x9d (PPM) that fits within a notebook type docking station or a desktop type docking station, or simply attaches to a docking housing 6 that is cabled to a keyboard and a monitor. (See FIG. 1). The ""742 Patent discloses an embodiment in FIGS. 10 and 11 where a magnetic disk drive and a PCB which carries a microprocessor are situated in a stacked arrangement. The ""742 Patent, however, does not show any particular structure for mounting the magnetic disk drive in the PPM, nor does it teach or suggest using an EMI shield between the magnetic disk drive and the PCB.
In U.S. Pat. No. 5,550,710 that issued in 1996 to Rahamim et al., also assigned to Hitachi, the inventors also disclose a PPM wherein a disk drive and main PCB are stacked. The ""710 Patent, however, focuses on a particular cooling structure for a PPM, and also does not disclose any particular structure for mounting the magnetic disk drive in the PPM or for shielding the drive from EMI emanating from the main PCB.
There remains a need, therefore, for an integrated computer module with a simple, rugged mechanism for securing the disk drive in the module and for effectively protecting the analog electronics associated with the disk drive from EMI generated by the microprocessor and associated circuitry.
In a first aspect, the invention may be regarded as an integrated computer module adapted for removable insertion into a docking bay within a host assembly, and upon such insertion for connecting to a host connector and thereby controlling a display device, the integrated computer module comprising: an enclosure defined by a front wall, a back wall opposite the front wall, a first side wall, a second side wall opposite the first guide wall, a floor wall and a ceiling wall; a main printed circuit board assembly (main PCBA) located in the enclosure, the main PCBA including a microprocessor clocked at high frequency and generating electromagnetic interference (EMI); a module connector electrically connected to the main PCBA and supported at the enclosure""s back wall for connection to the host connector upon insertion of the integrated module into the docking bay in the host assembly; a disk drive including a casting and a controller PCBA mounted on one side of the casting, the controller PCBA including integrated circuits that define a hard disk storage control subsystem that operates with relatively low amplitude signals that are subject to distortion from EMI; a conductor assembly electrically connecting the main PCBA to the controller PCBA; and an intermediate plate including a central section, a front edge, a back edge opposite the front edge, a first side edge, and a second side edge opposite the first side edge, the intermediate plate located between the disk drive""s controller PCBA and the main PCBA and attached to the enclosure to capture the disk drive in the enclosure and to protect the controller PCBA from EMI generated by the main PCBA. In the preferred embodiment, the main PCBA and the disk drive are located in a stacked arrangement within the enclosure, with the disk drive""s controller PCBA facing the main PCBA to reduce the length of the conductor assembly and minimize signal degradation.